DE L AWAR E Climate Change Impact Assessment PREPARED BY Division of Energy and Climate Delaware Department of Natural Resources and Environmental Control DE L AWAR E Climate Change Impact Assessment PREPARED BY Division of Energy and Climate Delaware Department of Natural Resources and Environmental Control February 2014 Cover photo credits: • Main photo of water sunset: Photos.com • Wilmington waterfront: Delaware Economic Development Office • Canoers: Delaware Department of Natural Resources and Environmental Control • Withered corn: Ben Fertig, Integration and Application Network, University of Maryland Center for Environmental Science • Farmer sweating: Photos.com • Beach house with waves: Wendy Carey, Delaware Sea Grant DE L AWAR E Climate Change Impact Assessment PREPARED BY Division of Energy and Climate Delaware Department of Natural Resources and Environmental Control Section 1: Summary and Introduction Table of Contents Executive Summary Chapter 1 – Introduction Section 2: Delaware’s Climate Chapter 2 – Delaware’s Historic Climate Trends Chapter 3 – Comparison of Observed and Modeled Trends Chapter 4 – Delaware’s Future Climate Projections Section 3: Delaware’s Resources Chapter 5 – Public Health Chapter 6 – Water Resources Chapter 7 – Agriculture Chapter 8 – Ecosystems and Wildlife Chapter 9 – Infrastructure Appendix: Climate Projections – Data, Models, and Methods Climate Projection Indicators Delaware Climate Change Impact Assessment | 2014 i ii Delaware Climate Change Impact Assessment | 2014 Delaware Climate Change Impact Assessment | 2014 iii iv Delaware Climate Change Impact Assessment | 2014 DE L AWAR E Climate Change Impact Assessment PREPARED BY Division of Energy and Climate Delaware Department of Natural Resources and Environmental Control Section 1: Summary and Introduction Front Matter Table of Contents Acknowledgments Acronyms and Abbreviations Additional Resources Executive Summary Chapter 1 – Introduction Delaware Climate Change Impact Assessment | 2014 Table of Contents Table of Contents Section 1 – Summary and Introduction Front Matter Figures and Tables ............................................................................................................................................................ xi Acknowledgments ......................................................................................................................................................... xiv Acronyms and Abbreviations ..................................................................................................................................... xvii Additional Resources ..................................................................................................................................................xviii Executive Summary ................................................................................................................1 1. Introduction 1.1. Purpose ....................................................................................................................................................................1-1 1.2. Scope .........................................................................................................................................................................1-1 1.3. Organization ...........................................................................................................................................................1-2 1.4. Methodology ..........................................................................................................................................................1-3 1.5. Climate 101 .............................................................................................................................................................1-4 1.5.1. Understanding the Language of Climate Science ................................................................................1-4 1.5.2. Understanding Climate Information .....................................................................................................1-7 1.5.3. Types and Sources of Greenhouse Gases ............................................................................................ 1-10 Section 2 – Delaware’s Climate 2. Delaware Climate Trends (Daniel J. Leathers) Ke y Te rm s ........................................................................................................................................................................2-2 Summary ..........................................................................................................................................................................2-3 2.1. Background ............................................................................................................................................................2-4 2.2. Data and Methods .................................................................................................................................................2-4 2.2.1. Statewide and Divisional Temperature, Precipitation, and Drought Index Data .........................2-4 2.2.2. Cooperative Daily Weather Station Data ..............................................................................................2-5 2.2.3. Methods .......................................................................................................................................................2-6 2.3. Climate Trends Analysis – Temperature ...........................................................................................................2-6 2.3.1. Statewide Results ........................................................................................................................................2-6 2.3.2. Temperature Summary ..............................................................................................................................2-9 2.4. Climate Trends Analysis – Precipitation ..........................................................................................................2-9 2.4.1. Statewide Results .......................................................................................................................................2-9 3. Comparing Observed and Modeled Historic Data (Katharine Hayhoe and Daniel J. Leathers) Ke y Te rm s ........................................................................................................................................................................3-1 3.1. Can Global Climate Models Reproduce Observed Historical Trends? .....................................................3-1 vi Delaware Climate Change Impact Assessment | 2014 Table of Contents 4. Delaware Climate Projections (Katharine Hayhoe, Anne Stoner, and Rodica Gelca) Summary ..........................................................................................................................................................................4-1 Ke y Te rm s ........................................................................................................................................................................4-2 List of Graphs for Temperature and Precipitation Indicators ..............................................................................4-4 4.1. Background ............................................................................................................................................................4-5 4.1.1. Observed and Projected Future Change ................................................................................................4-6 4.1.2. Implications for Delaware .........................................................................................................................4-6 4.2. Data and Methods ................................................................................................................................................4-7 4.2.1. Global Climate Models .............................................................................................................................4-7 4.2.2. Statistical Downscaling Model.................................................................................................................4-7 4.2.3. Station Observations ..................................................................................................................................4-8 4.2.4. Higher and Lower Scenarios ....................................................................................................................4-8 4.2.5. Uncertainty ..................................................................................................................................................4-9 4.3. Temperature-Related Indicators .........................................................................................................................4-9 4.3.1. Annual and Seasonal Temperatures ..................................................................................................... 4-10 4.3.2. Temperature Extremes ............................................................................................................................ 4-14 4.3.3. Energy-Related Temperature Indicators ............................................................................................. 4-19 4.4. Precipitation-Related Indicators ...................................................................................................................... 4-21 4.4.1. Annual and Seasonal Precipitation .....................................................................................................